Grim Feast - Mirage

The granularity-related inconsistency of means (GRIM) test is a simple statistical test used to identify inconsistencies in the analysis of data sets. The test relies on the fact that, given a dataset containing N integer values, the arithmetic mean is restricted to a few possible values: it must always be expressible as a fraction whose denominator is N and whose numerator is an integer. If the reported mean does not fit this description, there must be an error somewhere; the preferred term for such errors is "inconsistencies", to emphasise that their origin is, on first discovery, typically unknown. GRIM inconsistencies can result from inadvertent data-entry or typographical errors, or from scientific fraud. The GRIM test is most useful in fields such as psychology where researchers typically use small groups and measurements are often integers. The GRIM test was proposed by Nick Brown and James Heathers in 2016, following increased awareness of the replication crisis in some fields of science.